<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    async function main() {
      // return 123
      // return new Promise(
      //   // (resolve, reject) => resolve('OK')
      //   // (resolve, reject) => reject('NO')
      // )
      throw 'OH NO'
    }
    let result = main()
    console.log(result); // PromiseState = fulfilled PromiseResult = 123
  </script>
</body>
</html>